If you want to have the scare put into you, then a reading of Casti's X-Events ought to do a job. An x-event, as defined by the author, is short for an "extreme event"--a rare, unanticipated situation capable of creating an unprecedented hiccup in the flow of things. Finance, travel, communication and life as we know it will be forever altered.
In his new book, Casti sheds light on these terrifying moments.

Computers reside inside every home; everyone has a cell phone; virtually every car contains onboard electronics; and the consumption of oil is worldwide. Casti talks about a variety of different situations that would interrupt these modern conveniences. There are chapters devoted to global financial "black swans," robot rebellions, the termination of oil supplies, nuclear winter, the crash of the Internet, international viruses, and electromagnetic pulse bombs.

But don't be alarmed. These are potential scenarios--things that might happen. The sun will probably burn out before any of these events actually happens, but if you want to read what it might be like if every computer in the world stopped working, then pick up X-Events.